扩频系统中多普勒频偏快速估计算法的性能分析

The Performance of a Fast Doppler Shift Estimation Technique in DSSS System

研究了直接序列扩频系统中基于DFT技术的大多普勒频偏估计算法。在分析DFT处理前后信噪比,DFT输出信号包络概率分布函数的基础上,推导了多普勒频偏检测的虚警概率、检测门限、检测概率和信噪比之间的关系。并结合某特定LEO卫星通信系统应用,得到了各参数的选取方法以及多普勒频偏估计的性能。

A technique based on DFT was discussed,which can fast estimate large Doppler frequency shift in direct sequence spread spectrum system.After analyzing the SNR before and after DFT process module,and the PDF of DFT's output,the paper deduced theoretically the false alarm probability,detection threshold,detection probability and the relationship in frequency domain.A practical example applied in LEO satellite system illustrated how to choose parameters and the performance of the technique.